Lecture #4 and #5: Circulation And The Heart Flashcards
Fish blood circulation
Single loop:
Fish heart has 2 chambers
Gills —> artery —> heart —> tissues of the body —-> artery —-> back to gills
Mammal circulation
Double loop
- Mammal heart has 4 chambers
Difficulty returning blood through veins to heart
1. muscle movement to squeeze veins
• low muscle movement = poor circulation
2. One way veins
Cardinc cycle
Diastole and systole
Diastole
Relaxation
- atrium completely fills with blood
- ventricle partly fills with blood
Systole
Contraction
- atrium contracts first, ventricle completely fills with blood
~ 1/10th sec delay ~
- ventricles contracts while valves (bicuspid and tricuspid) between atria and ventricle closes
- valves between ventricles and arteries open, blood leaves heart
- valves between ventricles and arteries close as ventricle relaxes
Where is the natural pacemaker located?
right atrium
AV electrical node
electrical activity is focused on AV node before passing through ventricle
Heart conditions
Angina
Cardiac arrest
Heart murmur
Heart attack
Fibulation
Angina
Pain from blockage in coronary artery
Cardiac arrest
Heart stops beating from electrical problem
Heart murmur
Incomplete closure of valve
- makes heart work overtime
Heart attack
Blood flow to the heart is blocked
- can cause cardiac arrest
Fibulation
Fluttering of the heart due to electrical problems
Blood pressure
Force of blood against sidewalls of vessels
- amount of fluid goes up = cardiac output (pressure goes up)
- Friction goes up = pressure goes up
- Cross - sectional area = pressure goes down
•higher b.p at arterial end of capillary
• Lower b.p at venous end
Specific blood pressure
Taken in a specific area (ex: arm)
Systolic/diastolic
- 120/70 is average b.p
- 120 = systolic
- 70 = diastolic
What area of the heart has the largest cross-sectional area?
Capillaries
- low pressure
What causes high blood pressure (hypertension)?
- Salt intake
- Chronic stress
- Genetics
- Age (hardening of the arteries as you get older)
- Lack of exercise
- Fat intake (causes friction + reduces cross sectional area)
How does respiration work in fish?
Water in the and mouth passes over gills
How does the parallel current work (hypothetical)?
Water goes in and out in one direction, Blood goes in and out in the same direction
- 50% efficiency in oxygen exchange
- can’t take in oxygen after 50%
How does the counter current work?
Water goes in and out one direction, Blood goes in and out in the opposite direction
- 85% efficiency
- more O2 can be taken in after 85%
- Fish use this system
What do nasal passages do?
- Moisten air
- Warms air
- Filters air (nasal hair + mucus)
- Antimicrobials in mucus of nose
Trachea (wind pipe)
- cilated epithelium
- tracial rings (cartilage support)
Alveoli (Alveolus)
- each has a capillary network
- moist
- thin epithelium (simple squamos)
Breathing cycle
Inhalation
- ribs out, diaphram down
- lung volume increase
- pressure goes down (negative pressure)
- Air goes in
Exhalation
- opposite of inhalation
- ribs in, diaphram up, lung volume decreases, pressure goes up, air out
Elastic recoil
makes it easier to decrease lung volume and increase pressure
During gestation
Humans - embryo implates into uterin wall ~ 5 days
- placenta fully formed by 1 month
Respiatory system
- last to mature ~ 8 months
At birth - lungs take over
- uses lungs for the first time
Fetal hemoglobin
Higher efficiency for O2 than maternal hemoglobin
- ensures O2 crosses placenta
Lymphatic system
One way flow towards circulatory system
1. Immune response - Body’s defense (lymph node)
2. Return excess fluid to circulatory system
3. Returns proteins that leak out to the circulatory system
4. Capillary - like vessels called lacteals that pick up digested lipids
Components of blood
Red blood cells - iron
White blood cells
Platlets
Plasma - fluid
Gases (O2, CO2)
Glucose (sugar)
Proteins
Hormones - signals
Salts
